NIKKEI Asian Review- Five Japanese business groups won certification to bid on Iranian oil and gas development projects, according to the Middle Eastern country's state oil company.

National Iranian Oil announced Dec. 31 that 29 firms had pre-qualified to put in offers for Iranian energy projects. Inpex, Mitsui & Co., Mitsubishi Corp., Itochu and Japan Petroleum Exploration were the Japanese companies selected.

Others making the cut included Anglo-Dutch multinational Royal Dutch Shell and Russia's Gazprom. From Asia, there was the China Petroleum & Chemical group and China National Petroleum, as well as Korea Gas from South Korea.

In 2004, Inpex teamed with National Iranian and others in a joint exploration project in the South Azadegan oil field. But because of Western economic sanctions levied against Iran for its nuclear program, the company withdrew its participation in 2010, before any real development had begun.

However, Japanese businesses have been searching out opportunities to re-enter the market. Iran ranks fourth in the world in crude oil deposits and has the world's biggest natural gas reserves. Its vast natural resource supply is a draw for any Japanese energy developer, according to a source at a major trading house.

Iran's petroleum minister, Bijan Zanganeh, told oil executives at the end of 2015 that the government is opening 52 fields to foreign interests. The total investment in those oil fields is estimated to reach $30 billion. However, details on the fields as well as contractual specifications have not been disclosed. One official at a Japanese resource developer said it's taking a cautious approach to the opportunity while closely monitoring what will happen to Western sanctions.

For resource-poor Japan, diversifying its crude oil and gas procurement sources remains a key challenge. The past two to three years have seen a virtual freeze on resource development worldwide amid the slide in oil prices. But crude has recovered to the $50-per-barrel level, and many believe it will hit $60 this year. Demand for oil and gas is said to be rising in emerging nations, which may touch off a wider scramble for the resources.